Pumping-jack.



H. G. SMITH PUMPING JACK. APPLICATION FILED 111111112, 1908.

992,075. Patnted May 9, 1911.

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H. G. SMITH.

PUMPING JACK.

APPLICATION FILED JUNE 12, 1908.

Patented May 9, 1911.

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attain,

UNITED STATES E TENT OFFICE.

HERBERT Gr. SMITH, OF BARTLESVILLE, OKLAHOMA.

PUMPING-JACK.

To all whom it may concern:

Be it known that I, HERBERT G. SMrri-I, a citizen of the United States,residing at Bar tlesville, in the county of \Vashington and State ofOklahoma, have invented certain new and useful Improvements in Pumping-Jacks, of which the following is a specification, reference being hadtherein to the accompanying drawing.

My invention relates to machine elements, and especially to pumpingjacks and the like.

It has for its object the provision of means whereby motion may becommunicated from a rocking member to a reciprocating memher withoutdisturbing the alinement of the latter and without the use of rotatingbearlngs.

I shall describe the invention as embodied in a pumping jack, but ofcourse this is to be taken as definitive and not restrictive, sincenumerous other applications of the same principle may be made.

The type of pumping jack now generally in use is that having a rigidframe carrying a bell crank lever or rocker j ournaled in the frame atits angle with one arm dropping downward and connected with the pullrod, while the other extends horizontally forward and is connected withthe polished rod or sucker rod of the pump. This rod passes through across-head, above which is a clamp fastened to the rod. At the ends ofthis cross-head are side arms, these lying parallel and serving as linksto connect the lower crosshead with a fixed cross-head above. They aresecured in place by means of nuts. This forms a swinging joint, andsince it affords no support for the polished rod, the latter is held inplumb by means of an arc-shaped guide carried by the rocking lever andhaving its center in the axis of the lever. WVith this arrangement thereis constant Wear on all the bearings, and it is diflicult to gear up andungear, on account of the many parts requiring tools in theiradjustment.

According to my present improvement, I still make use of the rigid frameand the rocker lever connected through its lower arm to a pull rod andthrough its upper arm to the polished rod. Instead of circular bearingsfor the side arms or links, however, I provide what I may term rockerbearings in which there is little or no friction, the movement dependingon two surfaces com- Specification of Letters Patent.

Application filed June 12, 1908.

Patented May 9, 1911.

Serial No. 438,250.

ing together as cams without lateral displacement. The arc-shaped guidemay be employed or may be omitted, the complete improvementcontemplating its omission.

My present construction may be briefly described as a swinging jointcomposed of a pair of double-ended stirrups hung over rocking cams. Byproperly shaping the curved faces of these cams, the arc-shaped guidemay be done away with. Since the bearing points for the swingin jointconstantly change at both ends curing their movement, it is onlynecessary to adjust the parts so that the mean amplitude of change willequal the lateral displacement due to the arc of stroke, to keep thepull always perpendicular and the rod properly alined.

My invention is illustrated in the accompanying drawings wherein Figure1 shows a pumping jack of the type mentioned, with my improvementapplied thereto. Fig. 2 is a side view on an enlarged scale of the outerend of the rocking lever showing a bearing head. Fig. 3 is a face viewthereof. Fig, 4 is a side view of the lower cross bar with its bearingheads. Fig. 4 is an end view thereof. Fig. 5 is a face view of one ofthe double stirrups or side arms.

Referring to the drawings and especially to Fig. 1, the numeral 1represents a double frame, composed of two triangular side frames,having their apices 2 provided with bearings for the trunnions or stubshaft of the bell crank rocker lever 3. The lower arm of this rockerlever, indicated at 3, is connected by adjustable mechanism a to thepull rod 5 by means of which motion is communicated to the rocker andthence to the pump. The upper arm 3 of the rocker carries a metal headupon which is the usual arc-shaped guide, which however in this case isunnecessary and may be dispensed with.

Upon each side of the rocker head is a bearing head 8, and upon each ofthese bearing heads is hung a stirrup 9 forming the upper terminus of aside arm or link 10, which has at its lower end another stirrup 11 forengagement with a similar bearing head 12 of a cross arm 13. In order toprevent displacement of the stirrups from the bearing heads 8 and 12, Iprovide each of the former with an upraised flange 8 and each of thelatter with a similar upwardly extending flange 12. centrally drilled at14; to receive the polish The cross arm 13 is or sucker rod 7 beingattached thereto in any suitable manner, as by means of a clamp upon therod above the cross arm.

The operation of my lnvention will now be understood. At each stroke ofthe pull rod 5, (which is actuated by a suitable prime mover), therocker arm 8 turns upon 1ts pivot 2 and lifts the bearing heads 8through an arc having its center in the pivot. The bearing heads 8 rockin the stirrups 9 and lift the side arms 10 which lift the cross arm 13,and that in turn lifts the sucker rod. As the bearing head 8 rocks inthe stlrrup 9, different portions of the under face of the stirrup barcome in contact with and rest upon different portions of the upper faceof the bearing head, according to the shape of the contiguous bearingfaces.

As shown, the point of support shifts from the inner edge of the bearinghead at the be ginning of the stroke to the outer edge at the endthereof; and so long as this amphtude is equal. to the horizontaldisplace- 'provement.

' necessity for wrenches or other tools.

ment due to the arc of stroke, the pull of the sucker rod will bevertical at all times.

Sundry advantages will be at once apparent after reading thisdescription of my im- In the first place, it is cheaper than the oldconstruction because the arms may be made as simple castings. In thesecond place it is simpler and easier to gear up and ungear, there beingno nuts, and po 11 the third place, the life of all the parts islengthened, and especially the bearing parts of the swinging joint.These are usually the first to wear out in the entire jack, be-

' side involving the necessity for constant oiling and adjusting. isnecessary.

I am aware that some changes can be made in, shape and other matters ofdetail as well In my case none of this 'as in the method of applying mybearings bination the following instrumentalities: a

frame, a rocker lever journaled in said frame, a pull rod and source ofpower therefor, a polish rod, bearing heads on the rocker lever, eachhaving a portion of its periphery shaped to form a bearing surface, across arm on the polish rod carrying similar bearing heads, and linkspassing over and adapted to rock with rolling contact on the bearingsurfaces of said heads so as to constitute a substantially frictionlessparallel motion, substantially as described.

2. A pumping jack comprising the following instrumentalities: a frame, abell crank rocker lever journaled at its angle in said gether withbroad-faced bearing heads on the upper end of the rocker lever, an apertured cross arm receiving and holding the polish rod broad-faced bearingheads on the said cross arm, side links having terminal stirrups passingover said bearing heads with their inner surfaces resting and adapted torock upon the broad faces of the heads,said faces and stirrups havingsuch curvature, and being so proportioned that in all positions of thepolish rod power will be de liveredfrom the upper to the lower stirrupsin a vertical line.

3. A jack motion comprising the following instrumentalities: a frame orsupport carrying bearings, a rocker member journaled at one point insaid bearings and means to oscillate the same therein, a bearing head onthe oscillating member having an extended bearing surface curved on aradius greater than its own greatest dimension and adapted as a whole toswing in the arc of a circle, a reciprocatory member adapted to move ina line tangent to said arc, a bearing head on said reciprocatory memberarranged so that itsaxis is parallel at all points of its travel to thatof the bearing head on the rocker member, and a link connection betweenthe two bearing heads with a stirrup taking over the bearing on therocker head and adapted to rock thereon so as to constantly shift itspoint of support toward and away from the center of oscillation of therocker, sufliciently to compensate for the recession and approach of therocker head from and to the line of motion of the reciprocatory member"during oscillation; whereby for all positions of the rocker member,power will be delivered to the reciprocatory member in the direct lineof its motion.

4. A jack motion comprising the following instrumentalities: a frame orsupport carrying bearings, a rocker member journaled at one point insaid bearings and means to oscillate the same therein, a bearing head onthe oscillating member with an arc-shaped cam surface having its axis ofcurvature parallel to the axis of oscillation, a reciprocatory memberadapted to move in a line meeting the arc of oscillation in at least onepoint, a bearing head on said reciprocatory member arranged so that itsaxis is parallel at all points of its travel to that of the bearing headon the cam surface, and an intermediate power transmitting memberconnecting the two bearing heads, with an extended arc-shaped camsurface resting and adapted to rock on the cam surface. of therocker-member-bearing-head during its oscillation so as to constantlyshift its point of support toward and away from the center ofoscillation of the rocker sufiicient to com- In testimony whereof Iaffix my signature pensate :t'oii'1 thde fI'BCBSSiOal and a11)proa%h ofin presence of two witnesses. the rocker ea rom an to the ine 0 mo tionof the reciprobatory member; whereby HERBERT SMITH 5 for all positionsof said rocker member, Witnesses:

power will be delivered to the reciprocatory GRACE HERSHEY, member inthe direct line of its motion. BEN U. ATCI'IISON.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

